Gallon, Clean & Etch Krud Kutter, Brand Metal Clean & Etch Is Formulated To Same Time On Many Paint Projects By Cleaning & Etching The Paint Surface In 1 Step, Prepares Iron, Steel, Zinc, Aluminum, Galvanized Surfaces For Painting, Removes Rust, Oil, Grease & Dirt, Helps Prevent Paint Peeling, Chipping, Blistering, & Related Adhesion Problems, Use Indoors Or Out, Water Based Heavy Ventilation During Use Not Necessary, Odorless, Biodegradable, VOC Compliant.